Diabetic retinopathy

What is Diabetic Retinopathy?

Diabetic Retinopathy is a complication of Type I and Type II diabetes that affects the blood vessels inside the retina. It is a serious, sight-threatening disease and is the most common form of blindness in Australians under the age of 50. It generally affects both eyes, however, one eye may be damaged to a greater extent. Diabetes can also cause swelling of the macula as well which is known as Diabetic Macular Oedema. Diabetic Retinopathy can develop without affecting the vision so it is crucial to have regular eye examinations at least once a year with the Eye Specialist Institute to ensure early detection and prevention.

What causes Diabetic Retinopathy?

Diabetic Retinopathy is caused by high blood sugar levels in the retinal blood vessels. When the blood vessels are damaged they are unable to deliver oxygen and nutrients to retinal tissue, which is needed to maintain good vision. A damaged retina can cause blurriness and loss of vision

Who is at risk of Diabetic Retinopathy?

Diabetic Retinopathy is a complication of Type I and Type II diabetes. The chance of a person developing Diabetic Retinopathy increases the longer they have had diabetes for.The severity of this disease can also be intensified due to high blood pressure, high cholesterol levels and smoking. Pregnant women with underlying or gestational diabetes also have a greater likelihood of developing Diabetic Retinopathy.

What are the symptoms of Diabetic Retinopathy?

There are no early-stage signs of Diabetic Retinopathy. Over time, however, the Retinopathy can develop and cause vision loss. This is why it is essential to have a regular eye check-up to test for Diabetic Retinopathy and other undetectable eye conditions.

Vision loss caused by Diabetic Retinopathy can be due to:

Proliferative Retinopathy- Occurs when blood leaks from the abnormal vessels in the Retina causing people to see spots of blood in their vision. From time to time, these spots can clear without treatment. Although, bleeding can return and result in significant vision loss.

Diabetic Macular Oedema- Involves blurring of the central vision due to fluid leaks under the macula. Diabetic Macular Oedema can occur during any stage of Diabetic Retinopathy, however, it is most common in the later stages. Approximately 50% of people with Proliferative Retinopathy also have Diabetic Macular Oedema.

Retinal Examination- Using eye drops your ophthalmologist will dilate your pupils and use a slit lamp microscope to obtain a detailed view of the optic nerve, blood vessels and macula looking for any signs of diabetic damage.

Tonometry- A tool used to gage the pressure inside the eye. Tonometry is often used to detect Glaucoma, which can be predominant in cases of diabetes.

Optical Coherence Technology - Optical Coherence tomography (OCT) is a non-invasive imaging test which uses light waves to detect the presence of abnormal blood and fluid under the macula. It can be used to diagnose Diabetic Macular Oedema, how much fluid is present as well as monitor the eye’s response to treatment.

Fluorescein Angiography- This medical procedure involves fluorescein dye (vegetable based) being injected into a vein in the arm, the dye then travels through the circulatory system to the blood vessels in the eye. From here a series of photographs are taken as the dye passes through the retina. Any signs of abnormal vessels that are leaking will appear on the photographs. It can also highlight any leakage due to Diabetic Macular Oedema.

How is Diabetic Retinopathy treated?

There is currently 3 different methods of treatment available for Diabetic Retinopathy. These include laser, intravitreal injections of either anti-VEGF drugs or steroids or Vitrectomy surgery. In some cases vision can be improved with treatment, however, stabilising the disease is a common approach in Diabetic Retinopathy treatment. If the damage to the retina is extensive, the aim is to slow down the progress of Diabetic Retinopathy and minimise the patient’s level of vision loss. This can be achieved by controlling the diabetes and maintaining normal blood sugar, blood pressure and cholesterol levels.

A number of factors can influence the level of therapy required to treat your case of Diabetic Retinopathy. How far advanced the disease is and if the blood vessels are leaking, will determine the approach to take. Your Eye Specialist Institute retinal ophthalmologist will have a consultation with you to discuss in greater detail what option is best for you.Early stages of Diabetic Retinopathy are treated with laser surgery, a procedure called Pan-Retinal Photocoagulation (PRP), where a laser is used to target and shrink the abnormal blood vessels. Before surgery your ophthalmologist will administer dilating and anaesthetic drops, your pupil will remain dilated for a few hours following the operation so it is recommended that you arrange for someone else drive you home and that you bring a pair of dark sunglasses to wear after the procedure. It should be noted that due to a high number of laser burns being required to treat the leaky vessels, more than one session of PRP may be required. Some of the effects of PRP laser surgery can include some reduced peripheral and/or night vision. PRP is suitable treatment for Diabetic Retinopathy if the abnormal blood vessels have not started to leak, if they have a surgical procedure known as a Vitrectomy may be required.

Vitrectomy surgery is used to treat the late stages of Diabetic Retinopathy. This procedure is performed under local anaesthetic and involves the use of microscopic surgical tools to remove the Vitreous gel from the eye and insert a temporary gas bubble. The eye will then naturally fill with fluid and the gas bubble will be absorbed by the eye in 7-10days time. The eye may briefly feel red and gritty post-surgery, however the patient should notice a significant improvement in vision.

Both a Vitrectomy and PRP have a high success rate and are effective precaution to reduce vision loss. If the appropriate treatment is performed in due time, a patient with Diabetic Retinopathy has a less than 5% chance of becoming blind within five years. It should be noted that these treatments do not cure cases of Diabetic Retinopathy and once you have the disease you will always be at risk of new leaky blood vessels forming. This is why it is extremely important that you attend regular appointments with the Eye Specialist Institute to monitor this eye condition and access treatment to prevent vision loss.